摘要
污泥热水解过程中释放的腐殖酸对厌氧发酵产挥发性脂肪酸存在抑制作用。针对该问题,采用单独使用紫外光催化或添加CaCl_(2)化学絮凝及2种方法的耦合,以达到腐殖酸改性和去除的目的。结果表明:单独采用紫外光催化,腐殖酸的去除率仅达到17.68%,污泥发酵产酸率由原本的17.72%提高至20.73%;单独采用化学絮凝,腐殖酸的去除率为35.21%,发酵产酸率为27.96%;光催化耦合CaCl_(2)化学絮凝后,腐殖酸胶体的Zeta电位上升至-1.76 mV,腐殖酸的去除率可达68.50%,污泥发酵产酸效率提高至31.64%。其主要原因是,光催化使得腐殖酸的荧光基团发生了脱落和重排,大分子变为可溶性更高的小分子,故增强了腐殖酸与其他物质之间的相互作用,从而提高了腐殖酸的可絮凝性;光催化改性后的腐殖酸可与Ca^(2+)形成Ca-HA结合物,从而进一步降低了腐殖酸含量,最终缓解了腐殖酸对发酵产酸的抑制。本研究结果可为促进污泥发酵产酸、提高污泥有机物转化率提供参考。
Humic acids(HAs)released during the thermal hydrolysis of sludge had an inhibitory effect on the production of volatile fatty acids(VFAs)by anaerobic fermentation.UV photocatalysis,chemical flocculation and the coupling of the two methods were used to achieve the modification and removal of HAs.The results showed that the removal rate of HAs was only 17.68%,and the VFAs production efficiency increased from17.72% to 20.73% by using UV photocatalysis alone.The removal rate of HAs was 35.21%,and the acid production efficiency was 27.96% by using chemical flocculation alone.The Zeta potential of HAs colloid raised to-1.76 mV,meanwhile,the removal rate of HAs reached up to 68.50%,and the acidification efficiency up to 31.64%,due to UV photocatalysis coupled with calcium salt dosing.The shedding or rearrangement of fluorescent groups resulted in part of large molecules being decomposed into soluble small molecules,which enhanced the interaction between HAs and solvent or solute molecules.The photocatalytically modified HAs would form a Ca-HA conjugate with Ca^(2+),reducing the concentration of HAs,causing the alleviation of inhibition on sludge anaerobic fermentation for VFAs production.This study had a positive effect on removing HAs released by thermal hydrolysis and promoting anaerobic fermentation for VFAs production.
作者
黄芳
温佳欣
赵成
师铭泽
刘和
刘宏波
HUANG Fang;WEN Jiaxin;ZHAO Cheng;SHI Mingze;LIU He;LIU Hongbo(Laboratory of Environmental Microbiotechnology,School of Environmental and Civil Engineering,Jiangnan University,Wuxi 214122,China;Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,Suzhou 215009,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第6期2037-2045,共9页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51978313)。
关键词
腐殖酸
光催化
化学絮凝
厌氧发酵
挥发性脂肪酸
humic acids
UV photocatalysis
chemical flocculation
anaerobic fermentation
volatile fatty acids
